1、Designation: D 4953 06An American National StandardStandard Test Method forVapor Pressure of Gasoline and Gasoline-Oxygenate Blends(Dry Method)1This standard is issued under the fixed designation D 4953; the number immediately following the designation indicates the year oforiginal adoption or, in t
2、he case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers and is applicable to gasolinesand gasoline-oxygenate blends
3、 with a vapor pressure rangefrom 35 to 100 kPa (5 to 15 psi) (see Note 2). This test method,a modification of Test Method D 323 (Reid Method), providestwo procedures to determine the vapor pressure (Note 1)ofgasoline and gasoline-oxygenate blends.NOTE 1Because the external atmospheric pressure is co
4、unteracted bythe atmospheric pressure initially present in the air chamber, this vaporpressure is an absolute pressure at 37.8C (100F) in kilopascals (pounds-force per square inch). This vapor pressure differs from the true vaporpressure of the sample due to some small vaporization of the sample and
5、air in the confined space.NOTE 2Vapor pressure of gasoline or gasoline-oxygenate blendsbelow 35 kPa (5 psi) or greater than 100 kPa (15 psi) can be determinedwith this test method but the precision and bias (Section 11) do not apply.For materials with a vapor pressure greater than 100 kPa (15 psi),
6、use a 0to 200 kPa (0 to 30 psi) gauge as specified in the annex of Test MethodD 323.1.2 Some gasoline-oxygenate blends may show a haze whencooled to 0 to 1C. If a haze is observed in 9.4, it shall beindicated in the reporting of results. The precision and biasstatements for hazy samples have not bee
7、n determined (seeNote 7).1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this
8、standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific warningsare given in 7.5, 8.4.1, 8.5.1, 9.1, A1.1, and A1.1.3.2. Referenced Documents2.1 ASTM Standards:2D 323 Test Method for Vapor Pressure of Petroleum
9、Prod-ucts (Reid Method)D 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD 4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsD 5190 Test Method for Vapor Pressure of Petroleum Prod-ucts (Automatic Method)D 5191 Test Method for Vapor Pressure of Petroleum Pr
10、od-ucts (Mini Method)E1 Specification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 Definitions:3.1.1 Bourdon spring gauge, npressure measuring devicethat employs a bourdon tube connected to an indicator.3.1.2 Bourdon tube, nflattened metal tube bent to a curvethat straightens under interna
11、l pressure.3.1.3 dry method, nin vapor pressure methods, a specificempirical test method (D 4953) for measuring the vaporpressure of gasoline and other volatile products in whichcontact of the test specimen with water is not allowed.3.1.4 dry vapor pressure equivalent (DVPE), nvalue cal-culated by a
12、 defined correlation equation, that is expected to becomparable to the vapor pressure value obtained by TestMethod D 4953, Procedure A.3.1.5 gasoline-oxygenate blend, nspark-ignition enginefuel consisting primarily of gasoline with one or more oxygen-ates.3.1.6 oxygenate, noxygen-containing ashless
13、organiccompound, such as an alcohol or ether, which may be used asa fuel or fuel supplement. D 41751This test method is under the jurisdiction of Committee D02 on PetroleumProducts and Lubricants and is the direct responsibility of Subcommittee D02.08 onVolatility.Current edition approved Aug. 1, 20
14、06. Published August 2006. Originallyapproved in 1989. Last previous edition approved in 1999 as D 495399a.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the stand
15、ards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.7 vapor pressure, npressure exerted by the vapor of aliquid when in e
16、quilibrium with the liquid D 41753.2 Abbreviations:3.2.1 DVPE, ndry vapor pressure equivalent4. Summary of Test Method4.1 The liquid chamber of the vapor pressure apparatus isfilled with the chilled sample and connected to the vaporchamber at 37.8C (100F). The apparatus is immersed in abath at 37.8C
17、 (100F) until a constant pressure is observed.The pressure reading, suitably corrected, is reported as thevapor pressure.4.2 Procedure A utilizes the same apparatus and essentiallythe same procedure as Test Method D 323 with the exceptionthat the interior surfaces of the liquid and vapor chambers ar
18、emaintained completely free of water. Procedure B utilizes asemi-automatic apparatus with the liquid and vapor chambersidentical in volume to those in Procedure A. The apparatus issuspended in a horizontal bath and rotated while attainingequilibrium. Either a Bourdon gauge or pressure transducer can
19、be used with this procedure. The interior surfaces of the liquidand vapor chambers are maintained free of water.5. Significance and Use5.1 Vapor pressure is an important physical property ofliquid spark-ignition engine fuels. It provides an indication ofhow a fuel will perform under different operat
20、ing conditions.For example, vapor pressure is a factor in determining whethera fuel will cause vapor lock at high ambient temperature or athigh altitude, or will provide easy starting at low ambienttemperature.5.2 Petroleum product specifications generally include va-por pressure limits to ensure pr
21、oducts of suitable volatilityperformance.NOTE 3Vapor pressure of fuels is regulated by various governmentagencies.6. Apparatus6.1 The apparatus for ProcedureAis described inAnnexA1.6.2 The essential dimensions and requirements for the liquidand vapor chamber for Procedure B are identical with those
22、forProcedure A and described in Annex A1. External fittings andfeatures will vary depending on whether a gauge or transduceris used and the provision for rotating the apparatus in the bath.Details of a commercially available unit are shown in AnnexA2.7. Handling of Test Samples7.1 This section appli
23、es to both Procedure A and B.7.2 The extreme sensitivity of vapor pressure measurementsto losses through evaporation is such as to require the utmostprecaution and the most meticulous care in handling ofsamples.7.3 Sampling shall be done in accordance with the ReidVapor Pressure section (10.3) of Pr
24、actice D 4057 except forfuels containing oxygenates where the Water DisplacementProcedure section (10.3.1.8) of D 4057 must not be used.7.4 Sample Container Size:7.4.1 The size of the sample container from which the vaporpressure sample is taken shall be 1 L (1 qt). It shall be 70 to80 % filled with
25、 sample.7.4.2 The present precision statement has been derivedusing samples in 1-L (1-qt) containers. Samples taken incontainers of other sizes as prescribed in Practice D 4057 canbe used if it is recognized that the precision can be affected. Inthe case of referee testing the 1-L (1-qt) sample cont
26、ainer shallbe mandatory.7.5 Hazards:7.5.1 The vapor pressure determination shall be the first testwithdrawn from the sample container. The remaining sample inthe container cannot be used for a second vapor pressuredetermination. If necessary, obtain a new sample.7.5.2 Samples shall be protected from
27、 excessive heat priorto testing.7.5.3 Samples in leaky containers shall not be tested.Discard and obtain a new sample.7.6 Sample Handling TemperatureIn all cases, the samplecontainer and contents shall be cooled to 0 to 1C (32 to 34F)before the container is opened. Sufficient time to reach thistempe
28、rature shall be assured by direct measurement of thetemperature of a similar liquid in a like container placed in thecooling bath at the same time as the sample. See A1.3.1.8. Preparation of Apparatus8.1 This section applies to both Procedure A and ProcedureB.8.2 Verification of Sample Container Fil
29、lingWith thesample at a temperature of 0 to 1C, take the container from thecooling bath or refrigerator and wipe dry with absorbentmaterial. If the container is not transparent, unseal it, and usinga suitable gauge, confirm that the sample volume equals 70 to80 % of the container capacity (see Note
30、4). If the sample iscontained in a transparent glass container, verify that thecontainer is 70 to 80 % full by suitable means (see Note 4).NOTE 4For non-transparent containers, one way to confirm that thesample volume equals 70 to 80 % of the container capacity is to use adipstick that has been pre-
31、marked to indicate the 70 and 80 % containercapacities. The dipstick should be of such material that it shows wettingafter being immersed and withdrawn from the sample. To confirm thesample volume, insert the dipstick into the sample container so that ittouches the bottom of the container at a perpe
32、ndicular angle, beforeremoving the dipstick. For transparent containers, using a marked ruler orby comparing the sample container to a like container which has the 70and 80 % levels clearly marked, has been found suitable.8.2.1 Discard the sample if its volume is less than 70 % ofthe container capac
33、ity.8.2.2 If the container is more than 80 % full, pour outenough sample to bring the container contents within 70 to80 % range. Under no circumstance return any of the pouredout sample to the container.8.2.3 Reseal the container, if necessary, and return thesample container to the cooling bath.8.3
34、Air Saturation of the Sample in Sample Container:8.3.1 Transparent Containers OnlySince 8.2 does notrequire that the sample be opened to verify the sample capacity,it is necessary to unseal the cap momentarily before resealingD4953062it, so that the samples in transparent containers are treated thes
35、ame as samples in non-transparent containers.8.3.2 With the sample again at a temperature of 0 to 1C,take the container from the cooling bath or refrigerator, wipe itdry with an absorbent material, remove the cap momentarily,taking care that no water enters, reseal, and shake vigorously.Return it to
36、 the cooling bath or refrigerator for a minimum of2 min.8.3.3 Repeat 8.3.2 twice more. Return the sample to thecooling bath until the beginning of the procedure.8.4 Preparation of Liquid Chamber:8.4.1 Place the stoppered or closed liquid chamber and thesample transfer tube in a refrigerator or cooli
37、ng bath forsufficient time to allow the chamber and the transfer tube toreach a temperature of 0 to 1C (32 to 34F). Keep the liquidchamber upright and not immersed over the top of the couplingthreads. (WarningThe transfer connection must be keptcompletely dry during cooling. This can be accomplished
38、 byplacing the transfer connection in a water tight plastic bag.)8.5 Preparation of the Vapor Chamber:8.5.1 Connect the gauge or pressure transducer to the vaporchamber and make a water tight closure of the lower openingof the chamber where the liquid chamber attaches. Make surethat the vent hole in
39、 the vapor chamber connection is alsosecurely closed. (WarningMaking a water tight closure ofboth the liquid and vapor chambers is extremely important. Forsome samples containing oxygenated compounds, contact withwater can cause phase separation and invalidate results.)NOTE 5For some Test Method D 3
40、23 apparatus, a Number 6.5 rubberstopper has been found satisfactory. For the horizontal or Herzogapparatus, a Number 3 rubber stopper and a Number 000 cork in the venthole is satisfactory. Another procedure is to attach a spare liquid chamberto the vapor chamber during the conditioning period. A th
41、ird alternative isto utilize a cap threaded to match the threads of the vapor chamber.Several apparatus manufacturers have indicated the intention to supplysuch caps for equipment. In any procedure used, the interior surfaces ofthe vapor pressure apparatus and the sample must be kept completely free
42、of water.8.5.2 Immerse the vapor chamber in a water bath main-tained at 37.8 6 0.1C (100 6 0.2F) for not less than 20 min.The top of the vapor chamber must be at least 25 mm (1 in.)below the surface of the water (Procedure A). (In Procedure Bthe vapor chamber lies horizontally, completely immersed i
43、nthe water bath.) Do not remove the vapor chamber from thewater bath until the liquid chamber has been filled with sampleas described in 9.1.9. Procedure9.1 Sample TransferRemove the sample from the coolingbath, dry the exterior of the container with absorbent material,uncap, and insert the chilled
44、transfer tube (see Fig. 1). Removethe liquid chamber from the cooling bath and, using anabsorbent material, dry the threaded top and place the chamberin an inverted position over the top of the transfer tube. Invertthe entire system rapidly so that the liquid chamber is uprightwith the end of the tr
45、ansfer tube approximately 6 mm (0.25 in.)from the bottom of the liquid chamber. Fill the chamber tooverflowing. Withdraw the transfer tube from the liquid cham-ber while allowing the sample to continue flowing up tocomplete withdrawal. (WarningProvision shall be made forsuitable containment and disp
46、osal of the overflowing sample toavoid fire hazard.)9.2 Assembly of ApparatusImmediately remove the vaporchamber from the water bath and, as quickly as possible, drythe exterior of the chamber with absorbent material withparticular care given to the connection between the vaporchamber and the liquid
47、 chamber. Remove the closure from thevapor chamber and couple the filled liquid chamber to thevapor chamber as quickly as possible without spillage. Whenthe vapor chamber is removed from the water bath and driedand the closure is removed, connect it to the liquid chamberwithout undue movement that c
48、ould promote exchange ofroom temperature air with the 37.8C (100F) air in thechamber. Not more than 10 s should elapse between removingthe vapor chamber from the water bath and completion of thecoupling of the two chambers. With Procedure B it is necessaryto disconnect the spiral tubing at the quick
49、 action disconnectafter removing from the water bath and before making theconnection to the vapor chamber.9.3 Introduction of the Apparatus into Bath:9.3.1 Procedure ATurn the assembled apparatus upsidedown and allow all the sample in the liquid chamber to draininto the vapor chamber. With the apparatus still inverted, shakeit vigorously eight times lengthwise. With the gauge end up,immerse the assembled apparatus in the bath, maintained at37.8 6 0.1C (100 6 0.2F), in an inclined position so that theconnection of the liquid and vapor chambers is
